KR20050000722A - Small camera optical system - Google Patents

Abstract

PURPOSE: A small-sized camera optic system is provided to increase productivity by using conventional lenses, simplifying an assembling process, and minimizing a tolerance in the assembling process. CONSTITUTION: An image sensing chip(42) is installed on a substrate(40) in order to sense an image of a subject. A lens system(50) is used for focusing the image of the subject on an image sensing chip. A barrel(52) is used for supporting the lens system, aligning the lens system and the image sensing chip on the same axis, and separating the lens system and the image sensing chip from each other. A housing(54) is used for supporting the barrel and is coupled to the substrate. A bottom end of the barrel is in contact with a predetermined region of a surface of the image sensing chip.

Description

Small camera optical system

The present invention relates to a compact optical system for video communication, and more particularly, to a compact camera optical system that can be applied to a portable communication device.

The small camera optical system applied to the portable communication device can be divided into the optical system that can be largely adjusted and the optical system that does not need focus.

In the former case, a test procedure for focusing the lens system may be required during the assembly process, and thus productivity may be reduced, and particles may be generated due to burrs generated by a screw thread when focusing the lens, thereby reducing overall yield. have.

In the latter case, the lens support is integrally formed with the lens for auto focus. Therefore, in the case of using the latter optical system, the problem occurring in the former case can be improved. However, since the lens and its support must be formed integrally, the mold cost of the lens can be increased and the manufacturing cost can be increased. In addition, since the material of the support is the same as that of the lens, incident light may be diffusely reflected from the support to generate a ghost image.

In order to prevent the ghost image, a method of forming an anti-reflective pattern on the support of the same material as the lens has been proposed, but it is still difficult to completely remove the ghost image.

SUMMARY OF THE INVENTION The present invention has been made in an effort to improve the above-described problems of the prior art, and to provide a compact camera optical system capable of increasing productivity and yield and removing ghost images.

1 to 3 are cross-sectional views of the compact camera optical system according to the first to third embodiments of the present invention.

4 is an enlarged view of a portion C of FIG. 3.

5 and 6 are cross-sectional views of the compact camera optical system according to the fourth and fifth embodiments of the present invention, respectively.

* Description of Signs of Major Parts of Drawings *

40: substrate 42: image sensing chip

46: image sensing area 48: bonding wire

50, 60, 80: first to third lens system 54, 64, 84, 90: first to fourth housing

50a, 60b: first and second infrared cut filter

50b, 60a: first and second focusing lenses

52, 62: first and second barrels 52a: projections

56, 66: First and second elastic O-rings

58: Adhesive 59: Chin

70: cap layer 72: contact pad

84a, 92a: first and second shelves 84b, 92b: first and second supports

92: lower housing 94: upper housing

94a: protrusion L: lens

P1: wall W, W ': first and second windows

G1, G2: Groove

In order to achieve the above technical problem, the present invention provides a substrate, an image sensing chip mounted on the substrate to sense an image of a subject, a lens system focusing an image of the subject on the image sensing chip, and supporting the lens system. And an image sensing chip aligned with each other on the same optical axis while supporting a lens barrel and the tube spaced apart from the lens system and the image sensing chip at a distance corresponding to the focal length of the lens system and fastened to a substrate around the image sensing chip. Including a housing,

It provides a compact camera optical system, characterized in that the lower end of the barrel is in contact with a predetermined area of the surface of the image sensing chip.

According to the embodiment of the present invention, a projection having a predetermined length is formed around the barrel, and a jaw is formed so that the projection is caught by the housing.

In addition, an elastic member bonded to both the projection and the jaw is provided.

In addition, the lens system includes an infrared cut filter and a focusing lens, wherein the infrared cut filter is provided so as to cover the front surface of the inlet of the barrel in the upper portion of the barrel.

According to another embodiment of the present invention, the front of the barrel may be provided with a transparent cap layer covering the entire inlet of the barrel or an opaque cap layer may be provided, in the case of the opaque cap layer, a window in which light is incident therein is formed do.

An elastic member adhered to both may be provided between the infrared cut filter and the barrel. In addition, an elastic member bonded to both the cap layer and the barrel may be provided. In this case, a contact pad may be further provided between the elastic member and the cap layer.

The present invention also provides a substrate, an image sensing chip mounted on the substrate to sense an image of a subject, a lens system focusing the image of the subject on the image sensing chip, and the lens system while supporting the lens system. And a housing fastened to a substrate around an image sensing chip and spaced apart from the lens system and the image sensing chip at a distance corresponding to a focal length of the lens system while the lens system and the image sensing chip are aligned on the same optical axis. It provides a compact camera optical system, characterized in that the support is provided in the housing with a lower end in contact with a predetermined area of the surface of the image sensing chip.

The housing is provided with a shelf on which the lens system is placed, and the support is provided on the bottom of the shelf.

The housing includes a lower housing including some components of the lens system (eg, an infrared cut filter) and an upper housing including the remaining components of the lens system (eg, a focusing lens) and fastened to the lower housing.

Grooves are formed in the lower housing, and the upper housing is provided with a head portion inserted into the groove. In this case, a thread may be formed on the side of the groove, and a thread corresponding to the thread may be formed on the side of the protrusion.

The lower housing is provided with a shelf on which the groove and the infrared cut filter are placed with a wall in between. At this time, the height of the wall is preferably the same as the thickness of the infrared cut filter.

Using the present invention, since the conventional lens system can be used as it is, the assembling process is easy, and the focus test on the lens system itself is easy, so that the lens system can be checked before assembly. In addition, since the fastening of the upper housing and the lower housing is made outside the lens system, it is possible to completely exclude the influence of impurities caused by burrs generated during the fastening of the two housings, and the fastening by the screw coupling method may be performed. Tolerances that can occur at can be minimized. In addition, since the lens support is formed using a barrel that is completely different from the material of the lens, no diffuse reflection occurs from the support, and thus ghost images due to the diffuse reflection can be completely removed.

Hereinafter, a compact camera optical system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the process, the thicknesses of the regions shown in the drawings are exaggerated for clarity.

<First Embodiment>

Referring to FIG. 1, in the small camera optical system (hereinafter, referred to as a first optical system) according to the first embodiment of the present invention, an image sensing chip 42 is provided on a predetermined region of the substrate 40. The image sensing chip 42 is provided with an image sensing area 46 through which an image of a subject is sensed. The first lens system 50 is disposed above the image sensing chip 42. The first lens system 50 includes a first infrared cut filter 50a provided directly above the image sensing chip 42 and a first focusing lens 50b provided thereon. The first lens system 50 and the image sensing chip 42 are preferably all provided on the same optical axis. To this end, a first barrel 52 including and supporting the first lens system 50 is provided, and a lower end of the first barrel 52 is in contact with a predetermined region of the surface of the image sensing chip 42. The lower end of the first barrel 52 is preferably in contact with the surface of the image sensing chip 42 around the image sensing region 46, but is connected to the wire 48 bonding the image sensing chip 42 and the substrate 40. It is preferable that it is provided so that it may not contact. The material of the first barrel 52 is completely different from that of the first focusing lens 50b. Preferably, light incident through the window W (hereinafter, referred to as a first window) of the first barrel 52 is provided. This material prevents diffuse reflection. The first barrel 52 is supported by the first housing 54 which is coupled to the bottom of the substrate 40 around the image sensing chip 42. The diameter of the portion surrounding the image sensing chip 42 of the first housing 54 is wider than the diameter of the portion surrounding the first lens system 50. A protrusion 52a of a predetermined length is formed around the first barrel 52, and a jaw 59 corresponding to the protrusion 52a is formed in the first housing 54. The protrusion 52a is preferably a circular rim formed continuously along the circumference of the first barrel 52, but may be formed to be spaced apart at predetermined intervals. In other words, the protrusion 52a is preferably formed symmetrically around the first barrel 52. The protrusion 52a is symmetrically formed to apply uniform pressure to the first elastic member 56 described later. When the protrusion 52a is formed in such a shape, the jaw formed in the first housing 54 is also preferably provided in the same shape. Accordingly, the first housing 54 is first fastened to the substrate 40, and then the first barrel 52 is positioned inside the first housing 54 such that the lower end thereof contacts the predetermined area of the surface of the image sensing chip 42. The protrusion 52a formed in the first barrel 52 is caught by the jaw 59 formed in the first housing 54 when inserted into and fastened to the first barrel 52. As a result, the first barrel 52 is connected to the first housing 54. Supported by). In the process in which the first barrel 52 is fastened to the first housing 54, the inner surface of the portion in which the jaw 59 of the first housing 54 is formed is the portion of the portion in which the protrusion 52a of the first barrel 52 is formed. It adheres to the bottom surface.

On the other hand, when manufacturing the first barrel 52, the height of the first barrel 52, in particular, the height from the lower end to the first focusing lens 50b of the first lens system 50 of the first focusing lens 50b It is formed to correspond to the focal length. The jaw 59 of the first housing 54 is formed at a static height in consideration of the position of the protrusion 52a formed in the first barrel 52. Therefore, when the first barrel 52 is inserted into and fastened to the first housing 54, the lower end of the first barrel 52 contacts the predetermined region of the surface of the image sensing chip 42 and at the same time the first barrel 52 is closed. Projection 52a of the first housing 54 is accurately caught on the jaw 59 so that the lower end of the first barrel 52 does not come into contact with the surface of the image sensing chip 42, or the projection of the first barrel 52 is fixed. The situation where 52a does not come into contact with the jaw 59 of the first housing 54 does not occur.

Nevertheless, it may be difficult to completely exclude the possibility that the lower end of the first barrel 52 may be detached from the surface of the image sensing chip 42 during the movement of the first optical system shown in FIG. 1 or by an external impact. Therefore, even in such a situation, it may be provided with means for allowing the lower end of the first barrel 52 to be accurately attached to the surface of the image sensing chip 42.

The first elastic member, which is provided as one of the means, surrounds the circumference of the first barrel 52 between the projection 52a of the first barrel 52 and the jaw 59 of the first housing 54. (56). The first elastic member 56 is to give a cushion between the first barrel 52 and the first housing 54, and may be made of silicone or rubber having a predetermined elastic modulus, or may be a spring. have. When the first elastic member 56 is the spring, it is preferable that the first elastic member 56 is spaced apart at regular intervals along the circumference of the first barrel 52.

In FIG. 1, reference numeral 58 denotes a protrusion 52a, a first elastic member 56, and a first housing 54 of the first barrel 52 after the first barrel 52 is inserted into the first housing 54. The adhesive injected between the upper portion of the first barrel 52 and the upper portion of the first housing 54 to bond the jaw 59 of The adhesive 58 is preferably a material capable of completely blocking external humidity and light flowing from the outside to ensure reliability of the first optical system. By this adhesive 58, the first barrel 52 and the first housing 54 are completely engaged. The adhesive 58 is injected in a state where the first barrel 52 is fixed with a fixing jig from the outside.

Second Embodiment

In the case where the infrared cut filter is provided on the top of the barrel, the reference numerals (symbols) of the first embodiment are used for the members mentioned in the first embodiment, and description thereof is omitted. This fact applies to all examples below.

Specifically, referring to FIG. 2, in the small camera optical system (hereinafter referred to as a second optical system) according to the second embodiment of the present invention, an image sensing chip 42 is mounted on a predetermined region of the substrate 40. . The image sensing chip 42 is bonded to the substrate 40 by a bonding wire 48. The second lens system 60 is disposed above the image sensing chip 42. The second lens system 60 includes a second focusing lens 60a provided above the image sensing region 46 and a second infrared cut filter 60b provided above the second focusing lens 60a. The second lens system 60 configured as described above is provided on the same optical axis as the image sensing chip 42. To this end, a second barrel 62 including and supporting the second focusing lens 60a is positioned on a predetermined region of the surface of the image sensing chip 42. The lower end of the second barrel 62 is in contact with the surface of the image sensing chip 42 around the image sensing region 46. The second focusing lens 60a is disposed above the inner side of the second barrel 62. A first window (W) through which light reflected from a subject is incident is formed at an entrance of the second barrel (62), and a surface of the second focusing lens (60a) facing the subject contacts the first window (W). . The second infrared cut filter 60b is provided in front of the second barrel 62 and covers at least the entire surface of the first window W. As shown in FIG. Therefore, all light incident through the first window W passes through the second infrared cut filter 60b. By providing the second infrared cut filter 60b as described above, the second optical system can be free from the influence of temperature and humidity.

On the other hand, the second infrared cut filter (60b) may be attached to the upper surface of the second barrel (62), but may be preferably slightly spaced apart to prevent mutual damage due to friction or the like. To this end, a second elastic member 66 may be provided between the second barrel 62 and the second infrared cut filter 60b. The second elastic member 66 is preferably provided on the outer side of the upper surface of the second barrel 62, as shown in the figure. The second elastic member 66 is preferably made of the same material as the first elastic member (56 of FIG. 1) mentioned in the first embodiment. The second elastic member 66 and the second infrared cut filter 60b are bonded with the above adhesive. In order to provide the second elastic member 66 more stably, a groove having a shallow depth is formed in a portion where the second elastic member 66 of the second barrel 62 is mounted. The groove prevents the second elastic member 66 from moving horizontally. The second barrel 62 is fixed by a second housing 64 whose lower end is fastened to the substrate 40 around the image sensing chip 42. To this end, the upper side of the second barrel 62 is in close contact with the inner surface of the second housing 64.

On the other hand, the second infrared cut filter 60b is provided wider than the diameter of the second barrel 62. Therefore, the part out of the second barrel 62 of the second infrared cut filter 60b is in contact with the second housing 62. In order to stably support the second infrared cut filter 60b, the second housing 62 is provided with a jaw fitted with both ends of the second infrared cut filter 60b.

In the case of the second optical system, since the fixing jig fixes the second barrel 62 through the second infrared cut filter 60b, it is possible to prevent the fixing jig from directly contacting the adhesive.

Third Embodiment

This is the case where the cap layer for protecting the infrared cut filter is provided in front of the barrel.

Referring to FIG. 3, the compact camera optical system (hereinafter referred to as a third optical system) according to the third exemplary embodiment of the present invention includes a first lens system 50 in the second barrel 62. To this end, a groove for mounting the first infrared cut filter 50a is formed on the inner surface of the second barrel 62. The cap layer 70 is provided in front of the second barrel 62. The cap layer 70 is an opaque material layer, and a second window W ′ through which light incident from a subject passes is formed in the cap layer 70. The second window W 'is in the first window W, the diameter of which is smaller than the diameter of the first window W. A second elastic member 66 is provided between the second barrel 62 and the cap layer 70 to give a cushion to the cap layer 70. In order to stably secure the second elastic member 66, a groove is formed in a horizontal surface facing the cap layer 70 of the second barrel 62. The cap layer 70 extends out of the second barrel 62, the extended portion being supported by a second housing 64 that encloses and supports the second barrel 62. To this end, a jaw is formed so as to fit the extended portion of the cap layer 70 to the corresponding portion of the second housing 64.

Meanwhile, when the cap layer 70 is made of a transparent material layer, the cap layer 70 may be provided to cover the entire surface of the first window W without forming the second window W '.

In addition, as can be seen in FIG. 4, which shows an enlarged portion C of FIG. 3, the second elastic member 66, the second barrel 62, and the second housing 64 all sandwich the contact pad 72. In contact with the cap layer 70.

Fourth Example

The lens support is formed integrally with the housing.

Referring to FIG. 5, an image sensing chip 42 is mounted on a small camera optical system (hereinafter referred to as a fourth optical system) substrate 40 according to a fourth embodiment of the present invention, and the image sensing chip 42 is provided. The silver bonding wire 48 is bonded to the substrate 40. The third housing 84 surrounding the image sensing chip 42 and the third lens system 80 provided thereon is fastened to the substrate 40 around the image sensing chip 42. The third lens system 80 applies a conventional lens system as it is. Therefore, no additional cost is added to construct the third lens system 80. Nevertheless, the third lens system 80 may be configured similarly to the first and second lens systems 50 and 60, but may be configured differently. Reference numeral L symbolically represents a lens provided in the third lens system 80. The 1st shelf 84a for attaching the 3rd lens system 80 to the 3rd housing 84 is made. When the third lens system 80 is fastened to the third housing 84, the edge of the third lens system 80 extends over the first shelf 84a. Since the third lens system 80 and the image sensing chip 42 should be aligned on the same optical axis, the first shelf 84a is preferably formed symmetrically around the optical axis (not shown). A first support 84b for supporting the third lens system 80 is formed on an inner surface of the third housing 84 facing the surface of the image sensing chip 42, particularly on the rear surface of the first shelf 84a. The first support 84b is integrated with the third housing 84. The lower end of the first support (84b) is in contact with the surface of the image sensing chip 42, the length of the third lens system 80 to the third housing 84 in consideration of the focal length of the third lens system (80) When fastened, it is preferable that the focal point of the third lens system 80 can be accurately focused on the image sensing region 46.

As described above, since the third housing 84 of the fourth optical system is manufactured in consideration of the focal length of the third lens system 80, before the third lens system 80 is completely fastened to the third housing 84, By simply mounting the third lens system 80 to the third housing 84, it is possible to check whether the focal point of the third lens system 80 is exactly in the image sensing region 46. In other words, it is possible to check whether the third lens system 80 is defective before being fastened.

In addition, as described above, since the conventional lens system can be used as the third lens system 80 as it is, it can be more economical, and since the fastening is completed by inserting the fixed portion of the third housing 84, Defects can be minimized and yields naturally increased.

Fifth Embodiment

This is the case when the housing consists of upper and lower housings.

Referring to FIG. 6, in the compact camera optical system (hereinafter referred to as a fifth optical system) according to the fifth embodiment of the present invention, the fourth housing 90 is fastened to the substrate 40 around the image sensing chip 42. have. A first lens system 50 having the same optical axis is provided above the image sensing chip 42, and the fourth housing 90 supports the first infrared cut filter 50a of the first lens system 50 and senses the image. The upper housing 94 includes and supports a lower housing 92 surrounding the chip 42 and a first focusing lens 50b of the first lens system 50. The lower housing 92 is provided with a second shelf 92a in which the center area including the optical axis is empty and around which the first infrared cut filter 50a is placed. A second support 92b is formed on the rear surface of the second shelf 92a, the lower end of which is in contact with the surface of the image sensing chip 42. The second support 92b is formed to be equal to the first support 84b and serves to support the first lens system 50 and the upper housing 94. The first groove G1 is formed on the upper surface of the lower housing 92. The first groove G1 is formed to fasten the upper and lower housings 94 and 92, and a protrusion 94a inserted into the first groove G1 is formed in the upper housing 94. The protrusion 94a is formed by protruding the edge of the upper housing 94 downward. The wall P1 exists at the boundary between the third shelf 92a and the first groove G1 of the upper surface of the lower housing 92. The wall P1 is upwardly projected and its height is preferably equal to the thickness of the first infrared cut filter 50a placed on the third shelf 92a. The center including the optical axis of the upper housing 94 is empty, and a flat portion exists between the protrusion 94a and the center in contact with the wall P1 and the first infrared cut filter 50a. A second groove G2 for mounting the first focusing lens 50b is formed above this portion.

The fastening of the upper and lower housings 94 and 92 is achieved by coupling the protrusion 94a to the first groove G1. The protrusion 94a may be simply fitted to the first groove G1 to be coupled thereto. It can also be screwed together. For the latter case, a thread may be formed on the side surface of the first groove G1, and a thread corresponding thereto may be formed on the surface of the protrusion 94a.

As such, when the housing is divided into upper and lower housings, there is an advantage in that the mounting state of the image sensing chip and whether impurities are mixed before the upper housing is fastened to the lower housing in the assembling process.

While many details are set forth in the foregoing description, they should be construed as illustrative of preferred embodiments, rather than to limit the scope of the invention. For example, one of ordinary skill in the art may fasten the upper and lower housings in a manner other than screwing. In addition, the first support or the second support may be provided in the form of one continuous square pillar surrounding the image sensing area, it may be provided with a plurality of supports spaced apart at predetermined intervals around the image sensing area. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the technical spirit described in the claims.

As described above, the compact camera optical system according to the present invention can use the conventional lens system as it is, economical, easy to assemble, and can minimize the tolerance in the assembly process can increase the productivity and yield. In addition, the focus test on the lens system itself is easy to check whether the lens system is defective before assembly. In addition, since the fastening of the upper housing and the lower housing is made outside the lens system, it is possible to completely exclude the influence of impurities caused by the burrs generated during the fastening of the two housings, and the fastening by the screw coupling method is assembled. Tolerances that can occur during the process can be minimized. In addition, since the lens support is formed using a barrel which is completely different from the material of the lens, no diffuse reflection occurs from the support, and thus, the ghost image due to the diffuse reflection can be completely removed.

Claims (14)

Board; An image sensing chip mounted on the substrate to sense an image of a subject; A lens system focusing an image of the subject on the image sensing chip; A barrel supporting the lens system and separating the lens system from the image sensing chip at a distance corresponding to a focal length of the lens system while aligning the lens system and the image sensing chip on the same optical axis; And It includes a housing for supporting the barrel and fastened to the substrate around the image sensing chip, And a lower end of the barrel is in contact with a predetermined area of the surface of the image sensing chip. The compact camera optical system according to claim 1, wherein a projection having a predetermined length is formed around the barrel, and a jaw is formed so that the projection is caught by the housing. The compact camera optical system of claim 2, wherein an elastic member is provided between the protrusion and the jaw. The compact camera optical system of claim 1, wherein the lens system includes an infrared cut filter and a focusing lens, and the infrared cut filter is provided to cover the entire surface of the inlet of the barrel at an upper portion of the barrel. The compact camera optical system according to claim 1, wherein a transparent cap layer covering the entire entrance of the barrel is provided in front of the barrel. The compact camera optical system of claim 1, wherein an opaque cap layer is provided in front of the barrel, and a window into which light is incident is formed. 5. The compact camera optical system according to claim 4, wherein an elastic member bonded to both the infrared cut filter and the barrel is provided. The compact camera optical system according to claim 5 or 6, wherein an elastic member bonded to both the cap layer and the barrel is provided. The compact camera optical system of claim 8, further comprising contact pads between the elastic member and the cap layer. Board; An image sensing chip mounted on the substrate to sense an image of a subject; A lens system focusing an image of the subject on the image sensing chip; And The lens system is coupled to a substrate around the image sensing chip while supporting the lens system, and the lens system and the image sensing chip are spaced apart from each other by a distance corresponding to the focal length of the lens system while being aligned to the same optical axis. Including a housing, And a support having a lower end in the housing in contact with a predetermined area of the surface of the image sensing chip. 11. The compact camera optical system of claim 10, wherein a shelf on which the lens system is placed is provided in the housing, and the support is provided on a bottom surface of the shelf. The compact camera optical system of claim 10, wherein the housing comprises a lower housing for supporting some components of the lens system and an upper housing including the remaining components of the lens system and fastened to the lower housing. The compact camera optical system of claim 12, wherein a groove is formed on an upper surface of the lower housing, and a raised portion inserted into the groove is provided in the upper housing. 14. The compact camera optical system according to claim 13, wherein a thread is formed on the side of the groove, and a thread matching the thread is formed on the side of the protrusion.